Liquid crystal displays continue to be a dominant technology for flat panel displays. Liquid crystal displays that do not use polarizers, are reflective, and have intrinsic display memory are desirable in many situations. A number of reflective cholesteric liquid crystal displays has recently been developed. But these conventional reflective cholesteric liquid crystal displays typically suffer from one or more of the following deficiencies: switching between two states (e.g., planar state and focal-conic state) where one or both states are not stable under zero electric field; difficulty in fabricating black and white displays since one of the states must be colored (i.e., a color other than white or black); viewing angle dependency; poor light reflectivity; and poor contrast between the two states. There is a need, addressed by the present invention, to minimize or avoid one or more of above described problems.
The following documents may be relevant to the present invention:
Yang et al., U.S. Pat. No. 6,061,107.
Tamaoki et al., U.S. Pat. No. 6,103,431.
Yang et al., U.S. Pat. No. 5,847,798.
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